vfs: Add C++ guards to esp_vfs_dev.h

Closes https://github.com/espressif/esp-idf/issues/1069

components/vfs/include/esp_vfs_dev.h

@@ -12,11 +12,14 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#ifndef __ESP_VFS_DEV_H__
-#define __ESP_VFS_DEV_H__
+#pragma once
 
 #include "esp_vfs.h"
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /**
  * @brief Line ending settings
  */
@@ -81,4 +84,6 @@ void esp_vfs_dev_uart_use_nonblocking(int uart_num);
  */
 void esp_vfs_dev_uart_use_driver(int uart_num);
 
-#endif //__ESP_VFS_DEV_H__
+#ifdef __cplusplus
+}
+#endif